Mascara brush



FIG. 1 is a perspective view of a mascara brush showing our new design;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line showing of the stem is included for the purpose of illustrating a portion of the article that forms no part of the claimed design. 

The ornamental design for a mascara brush, as shown and described. 